// -*- mode: cpp; mode: fold -*-
// Description /*{{{*/
-// $Id: fileutl.cc,v 1.42 2002/09/14 05:29:22 jgg Exp $
/* ######################################################################
File Utilities
#include <signal.h>
#include <errno.h>
#include <glob.h>
+#include <pwd.h>
+#include <grp.h>
#include <set>
#include <algorithm>
#ifdef HAVE_LZMA
#include <lzma.h>
#endif
+#include <endian.h>
+#include <stdint.h>
-#ifdef WORDS_BIGENDIAN
-#include <inttypes.h>
+#if __gnu_linux__
+#include <sys/prctl.h>
#endif
#include <apti18n.h>
using namespace std;
-class FileFdPrivate {
- public:
-#ifdef HAVE_ZLIB
- gzFile gz;
-#endif
-#ifdef HAVE_BZ2
- BZFILE* bz2;
-#endif
-#ifdef HAVE_LZMA
- struct LZMAFILE {
- FILE* file;
- uint8_t buffer[4096];
- lzma_stream stream;
- lzma_ret err;
- bool eof;
- bool compressing;
-
- LZMAFILE() : file(NULL), eof(false), compressing(false) {}
- ~LZMAFILE() {
- if (compressing == true)
- {
- for (;;) {
- stream.avail_out = sizeof(buffer)/sizeof(buffer[0]);
- stream.next_out = buffer;
- err = lzma_code(&stream, LZMA_FINISH);
- if (err != LZMA_OK && err != LZMA_STREAM_END)
- {
- _error->Error("~LZMAFILE: Compress finalisation failed");
- break;
- }
- size_t const n = sizeof(buffer)/sizeof(buffer[0]) - stream.avail_out;
- if (n && fwrite(buffer, 1, n, file) != n)
- {
- _error->Errno("~LZMAFILE",_("Write error"));
- break;
- }
- if (err == LZMA_STREAM_END)
- break;
- }
- }
- lzma_end(&stream);
- fclose(file);
- }
- };
- LZMAFILE* lzma;
-#endif
- int compressed_fd;
- pid_t compressor_pid;
- bool pipe;
- APT::Configuration::Compressor compressor;
- unsigned int openmode;
- unsigned long long seekpos;
- FileFdPrivate() :
-#ifdef HAVE_ZLIB
- gz(NULL),
-#endif
-#ifdef HAVE_BZ2
- bz2(NULL),
-#endif
-#ifdef HAVE_LZMA
- lzma(NULL),
-#endif
- compressed_fd(-1), compressor_pid(-1), pipe(false),
- openmode(0), seekpos(0) {};
- bool CloseDown(std::string const &FileName)
- {
- bool Res = true;
-#ifdef HAVE_ZLIB
- if (gz != NULL) {
- int const e = gzclose(gz);
- gz = NULL;
- // gzdclose() on empty files always fails with "buffer error" here, ignore that
- if (e != 0 && e != Z_BUF_ERROR)
- Res &= _error->Errno("close",_("Problem closing the gzip file %s"), FileName.c_str());
- }
-#endif
-#ifdef HAVE_BZ2
- if (bz2 != NULL) {
- BZ2_bzclose(bz2);
- bz2 = NULL;
- }
-#endif
-#ifdef HAVE_LZMA
- if (lzma != NULL) {
- delete lzma;
- lzma = NULL;
- }
-#endif
- if (compressor_pid > 0)
- ExecWait(compressor_pid, "FileFdCompressor", true);
- compressor_pid = -1;
-
- return Res;
- }
- ~FileFdPrivate() { CloseDown(""); }
-};
-
// RunScripts - Run a set of scripts from a configuration subtree /*{{{*/
// ---------------------------------------------------------------------
/* */
{
if (Opts->Value.empty() == true)
continue;
-
+
+ if(_config->FindB("Debug::RunScripts", false) == true)
+ std::clog << "Running external script: '"
+ << Opts->Value << "'" << std::endl;
+
if (system(Opts->Value.c_str()) != 0)
_exit(100+Count);
}
return Dir + '/' + File;
}
/*}}}*/
+// flAbsPath - Return the absolute path of the filename /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+string flAbsPath(string File)
+{
+ char *p = realpath(File.c_str(), NULL);
+ if (p == NULL)
+ {
+ _error->Errno("realpath", "flAbsPath failed");
+ return "";
+ }
+ std::string AbsPath(p);
+ free(p);
+ return AbsPath;
+}
+ /*}}}*/
// SetCloseExec - Set the close on exec flag /*{{{*/
// ---------------------------------------------------------------------
/* */
signal(SIGCONT,SIG_DFL);
signal(SIGTSTP,SIG_DFL);
+ long ScOpenMax = sysconf(_SC_OPEN_MAX);
// Close all of our FDs - just in case
- for (int K = 3; K != sysconf(_SC_OPEN_MAX); K++)
+ for (int K = 3; K != ScOpenMax; K++)
{
if(KeepFDs.find(K) == KeepFDs.end())
fcntl(K,F_SETFD,FD_CLOEXEC);
return true;
}
/*}}}*/
+// StartsWithGPGClearTextSignature - Check if a file is Pgp/GPG clearsigned /*{{{*/
+bool StartsWithGPGClearTextSignature(string const &FileName)
+{
+ static const char* SIGMSG = "-----BEGIN PGP SIGNED MESSAGE-----\n";
+ char buffer[strlen(SIGMSG)+1];
+ FILE* gpg = fopen(FileName.c_str(), "r");
+ if (gpg == NULL)
+ return false;
+ char const * const test = fgets(buffer, sizeof(buffer), gpg);
+ fclose(gpg);
+ if (test == NULL || strcmp(buffer, SIGMSG) != 0)
+ return false;
+
+ return true;
+}
+ /*}}}*/
+// ChangeOwnerAndPermissionOfFile - set file attributes to requested values /*{{{*/
+bool ChangeOwnerAndPermissionOfFile(char const * const requester, char const * const file, char const * const user, char const * const group, mode_t const mode)
+{
+ if (strcmp(file, "/dev/null") == 0)
+ return true;
+ bool Res = true;
+ if (getuid() == 0 && strlen(user) != 0 && strlen(group) != 0) // if we aren't root, we can't chown, so don't try it
+ {
+ // ensure the file is owned by root and has good permissions
+ struct passwd const * const pw = getpwnam(user);
+ struct group const * const gr = getgrnam(group);
+ if (pw != NULL && gr != NULL && chown(file, pw->pw_uid, gr->gr_gid) != 0)
+ Res &= _error->WarningE(requester, "chown to %s:%s of file %s failed", user, group, file);
+ }
+ if (chmod(file, mode) != 0)
+ Res &= _error->WarningE(requester, "chmod 0%o of file %s failed", mode, file);
+ return Res;
+}
+ /*}}}*/
+
+class FileFdPrivate { /*{{{*/
+ public:
+#ifdef HAVE_ZLIB
+ gzFile gz;
+#endif
+#ifdef HAVE_BZ2
+ BZFILE* bz2;
+#endif
+#ifdef HAVE_LZMA
+ struct LZMAFILE {
+ FILE* file;
+ uint8_t buffer[4096];
+ lzma_stream stream;
+ lzma_ret err;
+ bool eof;
+ bool compressing;
+
+ LZMAFILE() : file(NULL), eof(false), compressing(false) { buffer[0] = '\0'; }
+ ~LZMAFILE() {
+ if (compressing == true)
+ {
+ for (;;) {
+ stream.avail_out = sizeof(buffer)/sizeof(buffer[0]);
+ stream.next_out = buffer;
+ err = lzma_code(&stream, LZMA_FINISH);
+ if (err != LZMA_OK && err != LZMA_STREAM_END)
+ {
+ _error->Error("~LZMAFILE: Compress finalisation failed");
+ break;
+ }
+ size_t const n = sizeof(buffer)/sizeof(buffer[0]) - stream.avail_out;
+ if (n && fwrite(buffer, 1, n, file) != n)
+ {
+ _error->Errno("~LZMAFILE",_("Write error"));
+ break;
+ }
+ if (err == LZMA_STREAM_END)
+ break;
+ }
+ }
+ lzma_end(&stream);
+ fclose(file);
+ }
+ };
+ LZMAFILE* lzma;
+#endif
+ int compressed_fd;
+ pid_t compressor_pid;
+ bool pipe;
+ APT::Configuration::Compressor compressor;
+ unsigned int openmode;
+ unsigned long long seekpos;
+ FileFdPrivate() :
+#ifdef HAVE_ZLIB
+ gz(NULL),
+#endif
+#ifdef HAVE_BZ2
+ bz2(NULL),
+#endif
+#ifdef HAVE_LZMA
+ lzma(NULL),
+#endif
+ compressed_fd(-1), compressor_pid(-1), pipe(false),
+ openmode(0), seekpos(0) {};
+ bool InternalClose(std::string const &FileName)
+ {
+ if (false)
+ /* dummy so that the rest can be 'else if's */;
+#ifdef HAVE_ZLIB
+ else if (gz != NULL) {
+ int const e = gzclose(gz);
+ gz = NULL;
+ // gzdclose() on empty files always fails with "buffer error" here, ignore that
+ if (e != 0 && e != Z_BUF_ERROR)
+ return _error->Errno("close",_("Problem closing the gzip file %s"), FileName.c_str());
+ }
+#endif
+#ifdef HAVE_BZ2
+ else if (bz2 != NULL) {
+ BZ2_bzclose(bz2);
+ bz2 = NULL;
+ }
+#endif
+#ifdef HAVE_LZMA
+ else if (lzma != NULL) {
+ delete lzma;
+ lzma = NULL;
+ }
+#endif
+ return true;
+ }
+ bool CloseDown(std::string const &FileName)
+ {
+ bool const Res = InternalClose(FileName);
+
+ if (compressor_pid > 0)
+ ExecWait(compressor_pid, "FileFdCompressor", true);
+ compressor_pid = -1;
+
+ return Res;
+ }
+ bool InternalStream() const {
+ return false
+#ifdef HAVE_BZ2
+ || bz2 != NULL
+#endif
+#ifdef HAVE_LZMA
+ || lzma != NULL
+#endif
+ ;
+ }
+
+
+ ~FileFdPrivate() { CloseDown(""); }
+};
+ /*}}}*/
// FileFd::Open - Open a file /*{{{*/
// ---------------------------------------------------------------------
/* The most commonly used open mode combinations are given with Mode */
-bool FileFd::Open(string FileName,unsigned int const Mode,CompressMode Compress, unsigned long const Perms)
+bool FileFd::Open(string FileName,unsigned int const Mode,CompressMode Compress, unsigned long const AccessMode)
{
if (Mode == ReadOnlyGzip)
- return Open(FileName, ReadOnly, Gzip, Perms);
+ return Open(FileName, ReadOnly, Gzip, AccessMode);
if (Compress == Auto && (Mode & WriteOnly) == WriteOnly)
return FileFdError("Autodetection on %s only works in ReadOnly openmode!", FileName.c_str());
if (compressor == compressors.end())
return FileFdError("Can't find a match for specified compressor mode for file %s", FileName.c_str());
- return Open(FileName, Mode, *compressor, Perms);
+ return Open(FileName, Mode, *compressor, AccessMode);
}
-bool FileFd::Open(string FileName,unsigned int const Mode,APT::Configuration::Compressor const &compressor, unsigned long const Perms)
+bool FileFd::Open(string FileName,unsigned int const Mode,APT::Configuration::Compressor const &compressor, unsigned long const AccessMode)
{
Close();
Flags = AutoClose;
TemporaryFileName = string(name);
free(name);
- if(Perms != 600 && fchmod(iFd, Perms) == -1)
+ // umask() will always set the umask and return the previous value, so
+ // we first set the umask and then reset it to the old value
+ mode_t const CurrentUmask = umask(0);
+ umask(CurrentUmask);
+ // calculate the actual file permissions (just like open/creat)
+ mode_t const FilePermissions = (AccessMode & ~CurrentUmask);
+
+ if(fchmod(iFd, FilePermissions) == -1)
return FileFdErrno("fchmod", "Could not change permissions for temporary file %s", TemporaryFileName.c_str());
}
else
- iFd = open(FileName.c_str(), fileflags, Perms);
+ iFd = open(FileName.c_str(), fileflags, AccessMode);
this->FileName = FileName;
if (iFd == -1 || OpenInternDescriptor(Mode, compressor) == false)
void* (*compress_open)(int, const char *) = NULL;
if (false)
/* dummy so that the rest can be 'else if's */;
-#define APT_COMPRESS_INIT(NAME,OPEN,CLOSE,STRUCT) \
+#define APT_COMPRESS_INIT(NAME,OPEN) \
else if (compressor.Name == NAME) \
{ \
compress_open = (void*(*)(int, const char *)) OPEN; \
- if (d != NULL && STRUCT != NULL) { CLOSE(STRUCT); STRUCT = NULL; } \
+ if (d != NULL) d->InternalClose(FileName); \
}
#ifdef HAVE_ZLIB
- APT_COMPRESS_INIT("gzip", gzdopen, gzclose, d->gz)
+ APT_COMPRESS_INIT("gzip", gzdopen)
#endif
#ifdef HAVE_BZ2
- APT_COMPRESS_INIT("bzip2", BZ2_bzdopen, BZ2_bzclose, d->bz2)
+ APT_COMPRESS_INIT("bzip2", BZ2_bzdopen)
#endif
#ifdef HAVE_LZMA
- else if (compressor.Name == "xz" || compressor.Name == "lzma")
- {
- compress_open = (void*(*)(int, const char*)) fdopen;
- if (d != NULL && d->lzma != NULL)
- {
- delete d->lzma;
- d->lzma = NULL;
- }
- }
+ APT_COMPRESS_INIT("xz", fdopen)
+ APT_COMPRESS_INIT("lzma", fdopen)
#endif
#undef APT_COMPRESS_INIT
#endif
d->openmode = Mode;
d->compressor = compressor;
#if defined HAVE_ZLIB || defined HAVE_BZ2 || defined HAVE_LZMA
- if (AutoClose == false && compress_open != NULL)
+ if ((Flags & AutoClose) != AutoClose && compress_open != NULL)
{
// Need to duplicate fd here or gz/bz2 close for cleanup will close the fd as well
int const internFd = dup(iFd);
if (d->lzma == NULL)
d->lzma = new FileFdPrivate::LZMAFILE;
d->lzma->file = (FILE*) compress_struct;
- d->lzma->stream = LZMA_STREAM_INIT;
+ lzma_stream tmp_stream = LZMA_STREAM_INIT;
+ d->lzma->stream = tmp_stream;
if ((Mode & ReadWrite) == ReadWrite)
return FileFdError("ReadWrite mode is not supported for file %s", FileName.c_str());
Args.push_back(a->c_str());
if (Comp == false && FileName.empty() == false)
{
- Args.push_back("--stdout");
+ // commands not needing arguments, do not need to be told about using standard output
+ // in reality, only testcases with tools like cat, rev, rot13, … are able to trigger this
+ if (compressor.CompressArgs.empty() == false && compressor.UncompressArgs.empty() == false)
+ Args.push_back("--stdout");
if (TemporaryFileName.empty() == false)
Args.push_back(TemporaryFileName.c_str());
else
errno = 0;
}
else
+ {
Res = Size - d->lzma->stream.avail_out;
+ if (Res == 0)
+ {
+ // lzma run was okay, but produced no output…
+ Res = -1;
+ errno = EINTR;
+ }
+ }
}
#endif
else
if (Res < 0)
{
if (errno == EINTR)
+ {
+ // trick the while-loop into running again
+ Res = 1;
+ errno = 0;
continue;
+ }
if (false)
/* dummy so that the rest can be 'else if's */;
#ifdef HAVE_ZLIB
int err;
char const * const errmsg = BZ2_bzerror(d->bz2, &err);
if (err != BZ_IO_ERROR)
- return FileFdError("BZ2_bzread: %s (%d: %s)", _("Read error"), err, errmsg);
+ return FileFdError("BZ2_bzread: %s %s (%d: %s)", FileName.c_str(), _("Read error"), err, errmsg);
}
#endif
#ifdef HAVE_LZMA
/* */
bool FileFd::Seek(unsigned long long To)
{
- if (d != NULL && (d->pipe == true
-#ifdef HAVE_BZ2
- || d->bz2 != NULL
-#endif
-#ifdef HAVE_LZMA
- || d->lzma != NULL
-#endif
- ))
+ Flags &= ~HitEof;
+
+ if (d != NULL && (d->pipe == true || d->InternalStream() == true))
{
// Our poor man seeking in pipes is costly, so try to avoid it
unsigned long long seekpos = Tell();
if ((d->openmode & ReadOnly) != ReadOnly)
return FileFdError("Reopen is only implemented for read-only files!");
- if (false)
- /* dummy so that the rest can be 'else if's */;
-#ifdef HAVE_BZ2
- else if (d->bz2 != NULL)
- {
- BZ2_bzclose(d->bz2);
- d->bz2 = NULL;
- }
-#endif
-#ifdef HAVE_LZMA
- else if (d->lzma != NULL)
- {
- delete d->lzma;
- d->lzma = NULL;
- }
-#endif
+ d->InternalClose(FileName);
if (iFd != -1)
close(iFd);
iFd = -1;
/* */
bool FileFd::Skip(unsigned long long Over)
{
- if (d != NULL && (d->pipe == true
-#ifdef HAVE_BZ2
- || d->bz2 != NULL
-#endif
-#ifdef HAVE_LZMA
- || d->lzma != NULL
-#endif
- ))
+ if (d != NULL && (d->pipe == true || d->InternalStream() == true))
{
- d->seekpos += Over;
char buffer[1024];
while (Over != 0)
{
if (To == 0 && FileName == "/dev/null")
return true;
#if defined HAVE_ZLIB || defined HAVE_BZ2 || defined HAVE_LZMA
- if (d != NULL && (
+ if (d != NULL && (d->InternalStream() == true
#ifdef HAVE_ZLIB
- d->gz != NULL ||
+ || d->gz != NULL
#endif
-#ifdef HAVE_BZ2
- d->bz2 != NULL ||
-#endif
-#ifdef HAVE_LZMA
- d->lzma != NULL ||
-#endif
- false))
+ ))
return FileFdError("Truncating compressed files is not implemented (%s)", FileName.c_str());
#endif
if (ftruncate(iFd,To) != 0)
// seeking around, but not all users of FileFd use always Seek() and co
// so d->seekpos isn't always true and we can just use it as a hint if
// we have nothing else, but not always as an authority…
- if (d != NULL && (d->pipe == true
-#ifdef HAVE_BZ2
- || d->bz2 != NULL
-#endif
-#ifdef HAVE_LZMA
- || d->lzma != NULL
-#endif
- ))
+ if (d != NULL && (d->pipe == true || d->InternalStream() == true))
return d->seekpos;
off_t Res;
// higher-level code will generate more meaningful messages,
// even translated this would be meaningless for users
return _error->Errno("fstat", "Unable to determine %s for fd %i", msg, iFd);
- ispipe = S_ISFIFO(Buf.st_mode);
+ if (FileName.empty() == false)
+ ispipe = S_ISFIFO(Buf.st_mode);
}
// for compressor pipes st_size is undefined and at 'best' zero
// for compressor pipes st_size is undefined and at 'best' zero,
// so we 'read' the content and 'seek' back - see there
- if (d != NULL && (d->pipe == true
-#ifdef HAVE_BZ2
- || (d->bz2 && size > 0)
-#endif
-#ifdef HAVE_LZMA
- || (d->lzma && size > 0)
-#endif
- ))
+ if (d != NULL && (d->pipe == true || (d->InternalStream() == true && size > 0)))
{
unsigned long long const oldSeek = Tell();
char ignore[1000];
FileFdErrno("lseek","Unable to seek to end of gzipped file");
return 0;
}
- size = 0;
+ uint32_t size = 0;
if (read(iFd, &size, 4) != 4)
{
FileFdErrno("read","Unable to read original size of gzipped file");
return 0;
}
-
-#ifdef WORDS_BIGENDIAN
- uint32_t tmp_size = size;
- uint8_t const * const p = (uint8_t const * const) &tmp_size;
- tmp_size = (p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0];
- size = tmp_size;
-#endif
+ size = le32toh(size);
if (lseek(iFd, oldPos, SEEK_SET) < 0)
{
{
if ((Flags & Compressed) != Compressed && iFd > 0 && close(iFd) != 0)
Res &= _error->Errno("close",_("Problem closing the file %s"), FileName.c_str());
-
if (d != NULL)
{
Res &= d->CloseDown(FileName);
#endif
}
-
-// Glob - wrapper around "glob()" /*{{{*/
-// ---------------------------------------------------------------------
-/* */
+// Glob - wrapper around "glob()" /*{{{*/
std::vector<std::string> Glob(std::string const &pattern, int flags)
{
std::vector<std::string> result;
return result;
}
/*}}}*/
-
-std::string GetTempDir()
+std::string GetTempDir() /*{{{*/
{
const char *tmpdir = getenv("TMPDIR");
tmpdir = P_tmpdir;
#endif
- // check that tmpdir is set and exists
struct stat st;
- if (!tmpdir || strlen(tmpdir) == 0 || stat(tmpdir, &st) != 0)
+ if (!tmpdir || strlen(tmpdir) == 0 || // tmpdir is set
+ stat(tmpdir, &st) != 0 || (st.st_mode & S_IFDIR) == 0 || // exists and is directory
+ access(tmpdir, R_OK | W_OK | X_OK) != 0 // current user has rwx access to directory
+ )
tmpdir = "/tmp";
return string(tmpdir);
}
+ /*}}}*/
+FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink) /*{{{*/
+{
+ char fn[512];
+ FileFd *Fd = new FileFd();
+
+ std::string tempdir = GetTempDir();
+ snprintf(fn, sizeof(fn), "%s/%s.XXXXXX",
+ tempdir.c_str(), Prefix.c_str());
+ int fd = mkstemp(fn);
+ if(ImmediateUnlink)
+ unlink(fn);
+ if (fd < 0)
+ {
+ _error->Errno("GetTempFile",_("Unable to mkstemp %s"), fn);
+ return NULL;
+ }
+ if (!Fd->OpenDescriptor(fd, FileFd::WriteOnly, FileFd::None, true))
+ {
+ _error->Errno("GetTempFile",_("Unable to write to %s"),fn);
+ return NULL;
+ }
+
+ return Fd;
+}
+ /*}}}*/
+bool Rename(std::string From, std::string To) /*{{{*/
+{
+ if (rename(From.c_str(),To.c_str()) != 0)
+ {
+ _error->Error(_("rename failed, %s (%s -> %s)."),strerror(errno),
+ From.c_str(),To.c_str());
+ return false;
+ }
+ return true;
+}
+ /*}}}*/
+bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/*{{{*/
+{
+ int fd;
+ if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly)
+ return _error->Error("Popen supports ReadOnly (x)or WriteOnly mode only");
+
+ int Pipe[2] = {-1, -1};
+ if(pipe(Pipe) != 0)
+ return _error->Errno("pipe", _("Failed to create subprocess IPC"));
+
+ std::set<int> keep_fds;
+ keep_fds.insert(Pipe[0]);
+ keep_fds.insert(Pipe[1]);
+ Child = ExecFork(keep_fds);
+ if(Child < 0)
+ return _error->Errno("fork", "Failed to fork");
+ if(Child == 0)
+ {
+ if(Mode == FileFd::ReadOnly)
+ {
+ close(Pipe[0]);
+ fd = Pipe[1];
+ }
+ else if(Mode == FileFd::WriteOnly)
+ {
+ close(Pipe[1]);
+ fd = Pipe[0];
+ }
+
+ if(Mode == FileFd::ReadOnly)
+ {
+ dup2(fd, 1);
+ dup2(fd, 2);
+ } else if(Mode == FileFd::WriteOnly)
+ dup2(fd, 0);
+
+ execv(Args[0], (char**)Args);
+ _exit(100);
+ }
+ if(Mode == FileFd::ReadOnly)
+ {
+ close(Pipe[1]);
+ fd = Pipe[0];
+ } else if(Mode == FileFd::WriteOnly)
+ {
+ close(Pipe[0]);
+ fd = Pipe[1];
+ }
+ Fd.OpenDescriptor(fd, Mode, FileFd::None, true);
+
+ return true;
+}
+ /*}}}*/
+bool DropPrivileges() /*{{{*/
+{
+ if(_config->FindB("Debug::NoDropPrivs", false) == true)
+ return true;
+
+#if __gnu_linux__
+#if defined(PR_SET_NO_NEW_PRIVS) && ( PR_SET_NO_NEW_PRIVS != 38 )
+#error "PR_SET_NO_NEW_PRIVS is defined, but with a different value than expected!"
+#endif
+ // see prctl(2), needs linux3.5 at runtime - magic constant to avoid it at buildtime
+ int ret = prctl(38, 1, 0, 0, 0);
+ // ignore EINVAL - kernel is too old to understand the option
+ if(ret < 0 && errno != EINVAL)
+ _error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret);
+#endif
+
+ // empty setting disables privilege dropping - this also ensures
+ // backward compatibility, see bug #764506
+ const std::string toUser = _config->Find("APT::Sandbox::User");
+ if (toUser.empty())
+ return true;
+
+ // uid will be 0 in the end, but gid might be different anyway
+ uid_t const old_uid = getuid();
+ gid_t const old_gid = getgid();
+
+ if (old_uid != 0)
+ return true;
+
+ struct passwd *pw = getpwnam(toUser.c_str());
+ if (pw == NULL)
+ return _error->Error("No user %s, can not drop rights", toUser.c_str());
+
+ // Do not change the order here, it might break things
+ if (setgroups(1, &pw->pw_gid))
+ return _error->Errno("setgroups", "Failed to setgroups");
+
+ if (setegid(pw->pw_gid) != 0)
+ return _error->Errno("setegid", "Failed to setegid");
+
+ if (setgid(pw->pw_gid) != 0)
+ return _error->Errno("setgid", "Failed to setgid");
+
+ if (setuid(pw->pw_uid) != 0)
+ return _error->Errno("setuid", "Failed to setuid");
+
+ // the seteuid() is probably uneeded (at least thats what the linux
+ // man-page says about setuid(2)) but we cargo culted it anyway
+ if (seteuid(pw->pw_uid) != 0)
+ return _error->Errno("seteuid", "Failed to seteuid");
+
+ // Verify that the user has only a single group, and the correct one
+ gid_t groups[1];
+ if (getgroups(1, groups) != 1)
+ return _error->Errno("getgroups", "Could not get new groups");
+ if (groups[0] != pw->pw_gid)
+ return _error->Error("Could not switch group");
+
+ // Verify that gid, egid, uid, and euid changed
+ if (getgid() != pw->pw_gid)
+ return _error->Error("Could not switch group");
+ if (getegid() != pw->pw_gid)
+ return _error->Error("Could not switch effective group");
+ if (getuid() != pw->pw_uid)
+ return _error->Error("Could not switch user");
+ if (geteuid() != pw->pw_uid)
+ return _error->Error("Could not switch effective user");
+
+#ifdef HAVE_GETRESUID
+ // verify that the saved set-user-id was changed as well
+ uid_t ruid = 0;
+ uid_t euid = 0;
+ uid_t suid = 0;
+ if (getresuid(&ruid, &euid, &suid))
+ return _error->Errno("getresuid", "Could not get saved set-user-ID");
+ if (suid != pw->pw_uid)
+ return _error->Error("Could not switch saved set-user-ID");
+#endif
+
+#ifdef HAVE_GETRESGID
+ // verify that the saved set-group-id was changed as well
+ gid_t rgid = 0;
+ gid_t egid = 0;
+ gid_t sgid = 0;
+ if (getresgid(&rgid, &egid, &sgid))
+ return _error->Errno("getresuid", "Could not get saved set-group-ID");
+ if (sgid != pw->pw_gid)
+ return _error->Error("Could not switch saved set-group-ID");
+#endif
+
+ // Check that uid and gid changes do not work anymore
+ if (pw->pw_gid != old_gid && (setgid(old_gid) != -1 || setegid(old_gid) != -1))
+ return _error->Error("Could restore a gid to root, privilege dropping did not work");
+
+ if (pw->pw_uid != old_uid && (setuid(old_uid) != -1 || seteuid(old_uid) != -1))
+ return _error->Error("Could restore a uid to root, privilege dropping did not work");
+
+ return true;
+}
+ /*}}}*/
projects / apt.git / blobdiff